//
// Created by Yemao Luo on 2021/9/7.
//

#include <stdio.h>
#include <math.h>

int main() {
    int a, b, c;
    scanf("%d %d %d", &a, &b, &c);
    if ((a + b) > c || (a + c) > b || (b + c) > a) {
        if (a == b || b == c || a == c) {
            if (a == b && b == c) {
                printf("Congruent triangle...");
            } else {
                printf("Isosceles triangle");
            }
        } else if (pow(a, 2) + pow(b, 2) == pow(c, 2) ||
                   pow(b, 2) + pow(c, 2) == pow(a, 2) ||
                   pow(a, 2) + pow(c, 2) == pow(b, 2)) {
            printf("Right triangle...");
        } else {
            printf("Not a triangle...");
        }
    }
    return 0;
}

